The field of the invention is systems and methods for medical imaging. More particularly, the invention relates to systems and methods for mapping and quantifying in-vivo blood flow stasis using medical imaging modalities, such as magnetic resonance imaging (MRI) and Doppler ultrasound.
Atrial fibrillation (AF) is a common cardiac arrhythmia and affects 33.5 million patients worldwide. It is associated with an increased risk of thrombus formation within the left atrial (LA) cavity. This increased risk is a major contributing factor to embolic stroke, the most serious complication of AF. Currently, an AF patient's annual stroke risk is estimated based on clinical risk models such as CHA2DS2-VASc scores. But, these scores have limited predictive accuracy (e.g., with C-statistics in the range of 0.55-0.67) because they are based on upstream clinical factors—such as age, gender, and diabetes—rather than individual physiologic factors implicating LA thrombus formation. MRI and Doppler echocardiography studies have shown that the increased risk of thrombus formation in AF patients may be related to flow abnormalities in the left atrium. This increased risk is because decreased blood flow velocity causes stasis, which increases the risk of blood clotting, and therefore stroke.
In light of the foregoing, it would be desirable to provide a system and method for mapping and quantifying in-vivo blood flow stasis.